Initialization offers you to prepare your external hard disk to accept data by splitting it into two steps. Initialize a storage device (much like the formatting procedure) is the method to erase the data on the drive and allow it to be workable again if it is not in service before. Part 3: How to Fix Disk Unknown, Not Initialized, Unallocated Problem?.Part 2: Why Disk Unknown, Not Initialized, Unallocated Error Occur?.